"""Floorplan detector service - OCR-based square meter detection."""
import asyncio
from models import Listing
from rec import floorplan
from repositories.listing_repository import ListingRepository
from tqdm.asyncio import tqdm
import multiprocessing


async def detect_floorplan(repository: ListingRepository) -> None:
    """Detect square meters from floorplan images for all listings."""
    listings = await repository.get_listings()
    cpu_count = multiprocessing.cpu_count() // 4
    semaphore = asyncio.Semaphore(cpu_count)

    updated_listings = [
        listing
        for listing in await tqdm.gather(
            *[_calculate_sqm_ocr(listing, semaphore) for listing in listings]
        )
        if listing is not None
    ]
    await repository.upsert_listings(updated_listings)


async def _calculate_sqm_ocr(
    listing: Listing, semaphore: asyncio.Semaphore
) -> Listing | None:
    """Calculate square meters from floorplan images using OCR."""
    if listing.square_meters is not None:
        return None
    sqms: list[float] = []
    for floorplan_path in listing.floorplan_image_paths:
        async with semaphore:
            estimated_sqm, _ = await asyncio.to_thread(
                floorplan.calculate_ocr, floorplan_path
            )
            if estimated_sqm is not None:
                sqms.append(estimated_sqm)
    max_sqm = max(sqms, default=0)  # try once, if we fail, keep as 0
    listing.square_meters = max_sqm
    return listing